Safety system for pipe lines



May 26, 1936. G. l. RHODES SAFETY SYSTEM FOR PIPE LINES .Filed NOV. 2l, 1930 gwwmtoz 620g@ Elfen/es EN @l-@Inw- Patented May 26, 1936 UNITED STATE-s SAFETY SYSTEM Fon PIPE LINES t George I.

Rhodes, Glen Ridge, N. J., assigner, by

direct and mesne assignments, of one-half to Ford, Bacon & Davis, Inc., New York, N. Y., a corporation of New Jersey, and one-half to Phillips Petroleum Company,

Bartlesville,

Okla., a corporation of Delaware Application November 2l, 1930, Serial No. 497,299

19 Claims.

The invention relates to safety systems for pipe lines conveying liquids or gases and has for its object to provide means for stopping the flow to a break or leak in the line, by means of automatic valves at `the beginning and at the end of the section of the line in which the break or leak occurs, the operation of the automatic valve at the up-stream end being controlled by diierential pressure actuated means, and that at the downstream end by a similar means, or by a/valve perated by reversal of iiow, the invention further contemplating a special arrangement of the pipe line and its controlling means at river crossings involving a7 division of the line into two or more branches, each branch being provided with an automatic valve near the up-stream end and a similar valve or a check valve closing against reverse flow near the down-stream end of the branch, the automatic valves being controlled by means of electric circuits, which, in turn, are controlled by a dierential flow meter installed in a cross connection between adjacent branches of the pipe line; whereby avbreak or a leak producing a `decrease in pressure in one of the branches will result in the closure of the automatic valves in that branch and a concurrent interruption of the electricl circuits controlling the automatic valves in the other branch, so that the ilow in the pipe line will be uninterrupted in the -latter branch.

The invention is illlustrated in the accompanying drawing-in which:-

Fig. 1 is a diagrammatic plan view of the system as applied to a river crossing in which the pipe line is divided into two branches with the automatic control of each.

Fig. 2 is a sectional elevation of a standard arrangement of orifice plate and flanges.

Fig. 3 is a perspective view of a suitable automatic emergency stop valve, one of which is interpolated in each branch.

Fig. 4 is a, diagrammatic involving three branches. Referring to the drawing, I indicates the main pipe line for conveying natural gas, oil, gasoline or the' like and,v as stated, the particular exemplaryillustration of the invention indicates such a pipe line installed in a river crossing, the line being divided into two branches 2, 2', each branch being fitted with a hand operated gate valve 3, 3 near its up-stream end and with an automatic plan view of a system emergency stop valve 4, Il preferably adjacent the respective valves 3,f3, said automatic stop valve being of a well known type commonly employed-in steam lines and being held normallyr (Cl. 13T-153) connected to the flow meter by pipes l2, i2' and In the particular installation, the pipe i3, i3' is cross connected betwen the ilanges Ill, il on the down-stream side of each plate and has connected therein a standard diiierential flow ,meter of the electrical contact making and/or,-

indicating type, conventionally illustrated at i5 and including an indicating element I5', which may be in the form of a pointer adapted to engage and close electric circuits through adjustable contacts 24 and 2i', when said indicating element of the meter is deflected due to a slight change in the pressures resulting from a change in the relative rates of ow in the respective branches 2, 2. Obviously other types of contact making iiow meters can readily be adapted to accomplish a like result.

In order to bring the indicating element l5 of the differential flow meter I5 to zero position, Iresulting from equalization of pressures When the normal ow through the respective branches 2, 2 is unbalanced due to difference in frictional resistance offered by the respective branches or other causes, avalved by-pass 40, 40' is disposed around each of the orice plates and associated flanges, so' that, bylregulatlng the flow through the respective Fby-passes, the pressures at the respective ends of the pipe I3, I3 connected t0 the ducts in the ianges I I, II may be equalized, under which conditions the indicating element I5 of the diierential flow meter I5 will stand at zero.

As stated, each of the automatic stop valves 4', 4 is held in open 'position by means o1' a latch, which is released, vto permit the valves to close, by means of an electromagnet or solenoid, such as I9, I9', which is energized by current from a V coil I9, lead 2U, through contacts 21 2| closed by a moving part valve 4' normally 22 of emergency step when the latter valve `is open, lead 23,

magnet I9 being from battery I1, lead I8, magnet v adjustable contact 24 of the diiierential iiow meter I5, indicating element I5' of said ilow meter through the metallic frame of said meter to the pipe line system, thence back to the battery by lead 26 connected to the respective branches of the pipe line. The circuit for magnet I9', which latter controls emergency stop valve 4', is as follows: battery I1, lead I8', magnet coil I9', lead .20', contacts 2|', 2l' normally closed by a moving part 22'v of the emergency stop valve 4, when the latter valve is open, lead 23' to adjustable contact 24' of the differential ilow meter I5, thence back to the battery as before. It will p be noted that each automatic stop valve controls contacts in the operating circuit of the stop valve in the other branch, so that, when onefof the emergency stop valves is closed, the circuit to the other will be interrupted at the contacts 2l, 2l or 2|', 2I and the corresponding stop valve. canot be automatically released by the coordinated electromagnet. Obviously other types of automatically closing valves can readily be adapted to a like service.

As shown, the down-stream end of each of the pipe line branches 2, 2' is provided with a check valve closing against reverse flow in the pipe line, said check valves being indicated at 5, 5' and each branch is also tted with a manually operated gate valve 8, 8'.

It will be understood that the various operating elements of the control system are located in suitable housings at or adjacent the ends of the respective multiple pipe lin'e sections.

Should a break or a leak occur in either of the branches of the pipe line, the automatic stop valve in that branch will be closed promptly, shutting oi the flow toward the break in the upstream end of the branch and the check valve, located in the down-stream end of the branch, will be closed by the reversal of the ow in said branch. For purposes of illustration, assume that a break or a leak occurs in the submerged portion of the branch 2 of Athe pipe line. leak will be to increase theV flow in said branch and reduce the pressure at the end ofthe cross connecting pipe Il, vhich is -tapped into the ange II adjacent the orice plate Il and this reduction in pressure will cause the indicator I5' of the differential flow meter I5 to engage the contact 2l and close the circuit through the magy`net or solenoid I9, which controls the automatic ,stop valve l, releasing the latch of said valve and permitting the valve to close, thereby stopping the ilow in the branch 2.` The closure of valve l will open the contacts 2l', 2I, in the tripping circuit of valve 4' and the flow interrupted through the branch 2' and the normal service of the pipe line will be maintained. 'I'he closure of the up-stream valve in the broken or leaking portion of the section 2 between the emergency stop valve 4 and the check valve B will cause the predominant pressure on the downstream side of the check valve 5 to close the latter promptly, if the leak has been insumcient in itself to cause a reversal of flow, and prevent the iiuid in the down-stream portion of the pipe line beyond the check valve from escap Obviously if the orices Il, Il' down-stream from the emergency stop valves I.

'4' the circuit breahng contacts on the stop valves z will be unnecessary, -since the closure of the stop valve will reduce the pressure on the down-stream side of the oriilce instead of increasing it as with the arrangement shown by Fig. 1, but the flow 'I'he effect of such will continue un-f are located meter instrument would be called upon to withstand the full line pressure between pipes I3 and I3 instead of the differential pressures as in the preferred arrangement described.

Obviously also the emergency stop valves could be closed through the action of contact making differential ilow meters connected across the flanges lIli and II of orice I4 and across the iianges III and II of orifice I4. The particular arrangement, including the cross connection through the flow meter is preferred, however, be-

cause it results in greater sensitiveness. There being no cross difierential pressure when there are no leaks, the Ainstrument can be set to operate at a very slight cross diiferential pressure resulting from a very slight leak in either line. 'I'his is of particular importance when handling liquids in long lines when there will be little increased total ow resulting even from a complete rupture of the line and accordingly the flow in aV broken line of a pair 'is practically limited to twice the normal ow. In the case of lines transporting compressed gases or expansible fluids a break even in a single line will result in a greatly increased iiow due to expansion of the uid to meet the reduced pressure.

As heretofore indicated, the frictional resistances to the flow in the branches 2, 2' are likely to be unequal and accordingly there will be an unequal flow of uid through the branches and, therefore, an initial cross differential pressure, unless means are provided for adjusting the differential pressures. This adjustment is provided by theby-passes I0, lIi'around the respective orifice plates and eachby-pass is equipped with a plug valve provided with means for locking it in place vafter the necessary adjustment has been made. By adjusting the by-pass ow around one or the other of the orifices, it will be possible to adjust -the differential to exact equality under normal operating conditions, which will be manifested by the pointer or indicating ineans of the y, flanges Il, Il and II, II' by the pipes I2, I2' and Although the exemplary system has been ijl- Y iustrated and described as including check valves, closing against reverse flow, in the down-stream ends of thev respective branches, it will be obvious that other types of automatic valves may be substituted for said check valves, when deemed expedient or advisable, in which case a substantial duplicate of the arrangement of the stop valves and automatic control as employed at the upstream ends of the branches may be installed in the down-stream ends thereof. It will also be understood that any suitable type of automatically closing valve may be substituted for that shown in Fig. 3 and also that the orifice-plates maybe replaced by Pitot tubes, Venturi tubes or other equivalent differential pressure producing means.

Likewise the cgntrol system is well adapted to pipe lines including multiple conduits generally.

While the system has been illustrated as in including the automatic stop valves, cross conillustrated in Fig. 3, in which the diiierential flow meter a: controls the automatic valves m, n in branches a and b, respectively, and, when either valve m or n is closed, it opens the circuit to the magnet controlling the other valve and the latter cannot be operated automatically by flow meter at'. Valve 11, however, is provided also with means for making and breaking the circuit tov the magnet controlling valve o, and valve o is provided with means for making and breaking the circuit to Vmagnet controlling valve n, the contacts of ow meter y being connected to the magnets of valves n and o in the manner i shown in Fig. 3, so that if valve n is closed by reason of a break or leak in branch b, neither valve m nor valve o can be: automatically tripped, as their respective trip circuits will be opened at the two sets of contacts controlled by valve n. If it is desired to have valves m and o automatically controlled when valve n is closed, a third contact making diierential flow meter z for` this purpose can be connected between the down-stream orices flanged in pipes a and c and additional con, tacts can be installed on valves o and m connected intothe tripping circuits of valves m and o respectively, as shown in dotted lines in Fig. 4. A break in branch b results in a prompt closure of valve n and a similar valve or a check valve in the down-stream end of said section, and similarly, a break in branch c or a eiects the closing of valve o or m and similar valves or check valves at the down-stream end of said branch, and in either case the flow istaken by the other two branches.

In its generic aspect, the invention includes what is, in eiect, a relay system adapted to bring about the closing of automatic valves at both ends of a section of a multiple branch pipe line in which section'a. break or even a relatively slight leak occurs, said relay including means utilizing .a cross diierential pressure between the branches to operate a differential llow meter which in tur-n controls the closing of the coordinate automatic stop valve or-valves.

What I claim is:

1. A pipe line including a feed pipe and a discharge pipe connected together by branch pipes, each branch pipe having means for obtaining differential pressures therein and a cut-off valve, and automatically operating means actuated by differential pressure in the branches for closing a valve in the branch in which pressure falls below that of the other branch.

2. A pipe line having admission and discharge pipes connected together by substantially parallel branch pipes, an electrically controlled valve in each branch pipe, and means functioning due to diierential pressures in the branches for closing the valve in the branch in which the pressure falls below that of the other branch.

3. A pipe line having admission and discharge pipes joined together by substantially parallel branch pipes, an orifice plate interposed ineach branch pipe, an electrically controlled valve interposed in each branch pipe, a differential meter, tubes connecting the diierential meter to the branches at one side of the orifice plates, and electrical means connecting said meter to said valves, whereby when the pressure in one of said branches at the down stream side of the orifice plate of that branch falls below that at the down stream side of the orifice plate of the other branch, the valve in the rst mentioned branch will be'closed.

4. A pipe line having admission and'discharge pipes connected by substantially parallel branches, a normally open valve in each of said branches, a Weight for closing each of said valves, electrically actuated means for releasing said weights, and means functioning due to difference in pressure between the ltwo branches for actuating the last mentioned means.

5. A pipe line including admission and dis- Y charge pipes connected by substantially parallel branch pipes of similar diameter, a normally open valve in each branch pipe, and means actuated by differential pressures in the branches for closing the valve in either one of the branches when the pressure in the latter varies from that in the other branch.

`6. A pipe line having admission and discharge pipes connected by substantially parallel branch pipes, a valve in each of said branch pipes, a t

weight for closing each of said valves, a trigger for normally holding each valve in open position, a solenoid for actuating each of said triggers, electric circuits in which the solenoids. are interposed, and a switch functioning due to diierences in pressure in the two branches for completing either'one of said circuits and closing the valve in the branch in which the pressure falls below that of the other branch.

7. A pipe line, comprising multiple conduits..

an automatic valve in each conduit, differential pressure controlled means operable selectively to stop the flow through the valve in that conduit in which a drop in pressure occurs with reference to the pressure in another of said conduits, and a plurality of pipes forming a cross connection between said means and said conduits to subject said means to duits. i

8. A pipe line, comprising multiple conduits, an automatic valve in each conduit, and means for eiecting the closing of the valve in that conduit in which a predetermined drop in pressure occurs pressure from said conwith respect to the pressure in the others, said means including a differential pressure actuated device, and means for communicating pressure 1from said conduits to said device to actuate the atter.

9. A pipe line including multiple conduits, spaced automatic valves in each conduit, one of said valves being operative to prevent back flow of theiluid in the conduit, and means operable upon a reduction of pressure in either conduit with respect to the pressure in the other to eiect the closure of the automatic valve toward the upfstream end of said conduit in which said reduction in pressure occurs.

l0. A pipe line including multiple conduits, an automatic valve in each conduit, means operable upon a reduction of pressure in either conduit with respect to the pressure in the other to effect `prevent automatic closing of the valve in the other conduit.

11. A pipe line including multiple conduits, an t automatic valve in each conduit and means to eiect closure of the automatic valve in a con-,1

duit in which occurs a predetermined reduction of pressure with respect to the pressure in the other conduit, said means'including a differential pressure actuated device connected to each of said conduits so as to be subject to pressure communicated therefrom, and a plurality of electric circuits controlled by said device.

12. A pipe line including multiple conduits, an automatic valve in each conduit, and differential pressure controlled means to effect closure of the automatic valve in a conduit in which occurs a predetermined reductionof pressure with respect to the pressure in the other conduit, pipes operatively connecting said conduits to said means, and a plurality of means respectively controlled by said valves and each effective on the closing of the valveby which it'is controlled 1z0-prevent automatic closing of another of said valves.

i 13. A pipe line including multiple conduits, an

automatic valve in each conduit, differential pressure producing. means in the coordinate conduits, a cross connection communicating with said conduits adjacent each of said means, a ow meter -in said cross connection, and means controlled.

by said meter .for eiecting closure of the associated valve in that one of said cross connected conduits in which occurs a decrease in pressure with respect to the pressure in the other.

14. A pipe line including multiple conduits, an automatic valve in each conduit, a diierential pressure producing means in each conduit, pipes respectively communicating with said conduits adjacent said differential pressure producing ter in each of said cross connections, electric circuits including contacts corresponding to said means to cross connect said conduits in pairs, a diilerential ilow meter in each ot said cross connections, electric circuits 'including contacts corresponding to said meters and engageable by the movable elements of the meters,` and electromagnets in said circuits controlling the operation of the respective valves.

15. A pipe line including multiple conduits, automatic` valves in\ each conduit, a diierential pressure producing means in each conduit, a cross connection between each pair of conduits communicating therewith adjacent said dierential pressure producing means, a differential flow memeters and engageable by the movable elements of the meters', and electromagnets in said circuits controlling the operation of the respective valves, each of said circuits also including contacts closed when the valves controlled by the other circuits are open and opened when said last named valves are closed. l

16. A pipe yline including a section having branches united at their ends to the main line, an automatic valve in the up-stream end of each branch, a check valve closing against reverse ilow in the downstream end of each branch, and means operable upon occurrence of a break or a leak in either branch to eiect closure of the automatic valve therein.

17. A pipe line including a section having branches united at their ends to the main line, an automatic valve inthe up-stream end of each branch, a check valve closing-against reverse flow in the downstream end. of each branch, means operable upon occurrence of a break or leak'in' either branch to effect closure oi the automatic valve therein, and means to prevent closing. of the automatic valve in one of said branches When the automatic valve in another of said brancheslis closed.

18. A pipe line including a section having branches united at their ends to the main line, an automatic valve in the up-stream end of each branch, at check valve closing against reverse flow in the downstream end of each branch, and

differential pressure controlled means cross connected between said branches to eiect closure of the automatic valve in the branch in which a break or a leak occurs.

19. A pipe line including a section having branches united attlieir ends to the main line, an electrically controlled stop valve in the upstream end of each branch, a check valve closing against reverse flow in the downstream end of each branch, a differential 7^pressure producing `meansI in each branch, a cross connection betweenvthe branches adjacent said means, a differential ow meter in said cross connection,- electric circuits including contacts engageable by a movable element of said meter, and electromagnets in said circuits controlling the operation of the respective stop valves.

GEORGE I. RHODES. y 

